Needle fixture of a probe card in semiconductor inspection equipment and needle fixing method thereof

ABSTRACT

A needle fixture of a probe card and a needle fixing method in semiconductor inspection equipment include a needle fixture of a probe card in semiconductor inspection equipment including a printed circuit board; a needle fixture installed in the printed circuit board; a resin unit affixing a probe needle to the needle fixture using an adhesive; and a separation preventer for preventing separation of the resin unit from the needle fixture, wherein the separation preventer includes: a plurality of notches formed along a bottom surface of the needle fixture; and the adhesive filling the plurality of notches.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a probe card of semiconductorinspection equipment. More particularly, the present invention relatesto a needle fixture of the probe card and a needle fixing method to theprobe card using an adhesive wherein the configuration of the needlefixture is changed to strengthen the attachment of the probe needle.

[0003] 2. Description of the Related Art

[0004] In general, a semiconductor memory device is produced byperforming two processes. First, a fabrication process for patterningthe semiconductor memory device on a wafer is performed. Subsequently,an assembly process for assembling each semiconductor memory device onthe wafer to each chip is performed. In addition, before performing theassembly process, an electric die sorting (EDS) process is performed toinspect an electric characteristic of each chip included in a wafer.

[0005] In operation, inspection equipment of the EDS process applies anelectric signal to each chip on the wafer, and determines whether eachchip is a pass, i.e., a good chip, or a fail, i.e., a bad chip, byinspecting the electric signal. Accordingly, the EDS process is able toidentify each bad chip fabricated on the wafer. Most inspectionequipment includes a probe card having a needle for applying theelectric signal to the chip on the wafer. A semiconductor chip (device)determined to be a good chip in the test using the probe card isproduced as a final product through a subsequent package process.

[0006] During the electric characteristic inspection of a chip of asemiconductor wafer, a needle of a probe card is contacted with anelectrode pad of the semiconductor wafer, a measuring current is passedthrough the needle, and an electric characteristic is measured.Therefore, to measure the electric characteristic of the electrode padon the wafer accurately, precise contact between the needle and theelectrode pad is required.

[0007] When a semiconductor chip is tested using a conventional probecard, to ensure the operation reliability, i.e., whether the chip isfunctional, the temperature of the stage loading a wafer is varied from−40° C. to +125° C. In a conventional probe card, the probe needle isaffixed to the needle fixture using an adhesive, such as a syntheticresin. Therefore, due to the temperature variation, the adhesion unitrepeatedly contracts and expands, thereby generating a crack in theadhesion unit and thereby causing the probe needle to separate from theneedle fixture. As a result, the reliability of the chip test isdiminished. Moreover, changing a probe card after the adhesion unitbecomes cracked or the probe needle has separated from the needlefixture increases production costs.

SUMMARY OF THE INVENTION

[0008] To overcome the above-described problems, it is a first featureof an embodiment of the present invention to provide a needle fixture ofa probe card of semiconductor inspection equipment that improves theperformance of an adhesion unit for affixing a probe needle to a needlefixture, to prevent a crack of the adhesion unit, or to inhibitseparation of the adhesion unit from the needle fixture. It is a secondfeature of an embodiment of the present invention to provide a needlefixing method in a probe card of semiconductor inspection equipmentfixing a probe needle to a needle fixture using an adhesive.

[0009] To provide the first feature of an embodiment of the presentinvention, there is provided a needle fixture of a probe card insemiconductor inspection equipment including a printed circuit board; aneedle fixture installed in the printed circuit board; a resin unitaffixing a probe needle to the needle fixture using an adhesive; and aseparation preventer for preventing separation of the resin unit fromthe needle fixture, wherein the separation preventer includes: aplurality of notches formed along a bottom surface of the needlefixture; and the adhesive filling the plurality of notches.

[0010] To provide the second feature of an embodiment of the presentinvention, there is provided a needle fixing method in a probe card ofsemiconductor inspection equipment fixing a probe needle to a needlefixture using an adhesive, including forming a plurality of notchesalong a bottom surface of the needle fixture; depositing a first resinlayer on the bottom surface of the needle fixture to cover and fill theplurality of notches; depositing a second resin layer on a predeterminedposition of the probe needle; contacting an exposed bottom surface ofthe first resin layer with an exposed upper surface of the second resinlayer; and heating the first and the second resin layers to melt andfuse the first and second resin layers.

[0011] Further, depositing the first resin layer may include depositingthe first resin layer to a uniform predetermined thickness over and inthe plurality of notches on the bottom surface of the needle fixture.

[0012] Preferably, the adhesive is an epoxy resin. Preferably, theplurality of notches are formed along the entire bottom surface of theneedle fixture.

[0013] In a preferred embodiment of the present invention, a sidesectional shape of the plurality of notches is a polygon. Morespecifically, the polygon may be a trapezoid.

[0014] In an alternate embodiment of the present invention, a sidesectional shape of the plurality of notches is a curve. Morespecifically, the curve may have the shape of the Greek letter “Ω”.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To provide a more complete understanding of the present inventionand the features and advantages thereof, reference is now made to thefollowing descriptions taken in conjunction with the accompanyingdrawings, in which like reference numerals denote like elements, and inwhich:

[0016]FIG. 1A illustrates a configuration of a probe card according to apreferred embodiment of the present invention;

[0017]FIG. 1B illustrates a configuration of a probe card according toan alternate embodiment of the present invention;

[0018]FIG. 2 illustrates a plan view of the bottom of a needle fixtureof FIG. 1A;

[0019]FIG. 3 illustrates a method for adhering a probe needle to theneedle fixture of FIG. 1A; and

[0020]FIG. 4 is a schematic diagram of semiconductor inspectionequipment applying the probe card of FIG. 1A.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Korean Patent Application No. 2002-39039, filed Jul. 5, 2002, andentitled: “Needle Fixture of a Probe Card in Semiconductor InspectionEquipment and Needle Fixing Method Thereof,” is incorporated byreference herein in its entirety.

[0022] The present invention will now be described more fullyhereinafter with reference to the accompanying drawings, in whichpreferred embodiments of the invention are shown. The invention may,however, be embodied in different forms and should not be construed aslimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the invention to those skilled in theart.

[0023]FIG. 1A illustrates a probe card 10 according to a preferredembodiment of the present invention. FIG. 1B illustrates a probe card 10according to an alternate embodiment of the present invention. FIG. 2illustrates a plan view of a bottom of a needle fixture of FIG. 1A.

[0024] As shown in FIGS. 1A, 1B, and 2, the probe card 10 includes aprinted circuit board 11, a probe needle 13, and a needle fixture 15.The printed circuit board 11 is a ring-shaped insulation plate. Theprinted circuit board 11 of the probe card includes a plurality of pinconnectors 11 a, as multiple conductive objects, formed thereon. A probeneedle 13 is installed at a bottom surface of the printed circuit board11 through an intermediate needle fixture 15. The probe needle 13applies an electric current to measure an electric characteristic whenthe probe needle 13 is contacted with an electric pad of a wafer.

[0025] The printed circuit board 11 further includes a deviceidentification hole 11 b for identifying a semiconductor devicecontacted with the middle of the printed circuit board 11, wherein thedevice identification hole 11 b fixes the needle fixture 15 through anintermediate supporting plate 17. The middle portion of the supportingplate 17 and the needle fixture 15 also include correspondingidentification holes 17 a and 15 c, respectively.

[0026] A bottom of the needle fixture 15 is sloped at a predetermineddegree. The probe needle 13 is affixed to the needle fixture 15 at apredetermined degree corresponding to the slope using an adhesive or aresin 19, such as an epoxy resin. A rear of the probe needle 13 isconnected with a pattern (not shown) of the printed circuit board 11. Asurface of the needle fixture 15 that is in contact with the resin 19has a separation preventer 20 for preventing separation of the resin 19from the bottom of the needle fixture 15.

[0027] The separation preventer 20 includes a plurality of notches 15 aand corresponding tabs 15 b formed along a bottom surface of the needlefixture 15. A resin unit 19 a fills each of the plurality of notches 15a. The plurality of notches 15 a increase the contact area with theresin 19, and are preferably formed along the entire bottom surface ofthe needle fixture 15. A side sectional shape of the plurality ofnotches 15 a may be a polygon, preferably a trapezoid. Each of theplurality of notches 15 a includes an opening 15 d therein.

[0028] In FIG. 1B, an alternate embodiment of the separation preventer20′ includes a plurality of notches 15 a′ and corresponding tabs 15 b′formed along a bottom surface of the needle fixture 15. In thisalternate embodiment, the plurality of notches 15 a′ has a sidesectional shape of a curve, preferably, in the shape of the Greek letteromega (Ω). As in the preferred embodiment, a resin unit 19 a′ fills eachof the plurality of notches 15 a′. The plurality of notches 15 a′increase the contact area with the resin 19′, and are preferably formedalong the entire bottom surface of the needle fixture 15. In addition,each of the plurality of notches 15 a′ a includes an opening 15 d′therein.

[0029] Since a shape of the plurality of notches 15 a is a trapezoid oran “Ω” shape 15 a′, a first width “T” measured along a rear surfaceopposite the opening 15 d or 15 d′ is larger than a second width “t,”which is the distance of the opening 15 d or 15 d′. Accordingly, theresin unit 19 a or 19 a′ is not easily extracted from the notch 15 a or15 a′. When the resin 19 or 19′ is contracted in the case of a lowtemperature test, the trapezoidal or omega-shape of the notches in theseparation preventer exhibits enhanced effects.

[0030]FIG. 3 illustrates a method for adhering a probe needle 13 to thebottom of the needle fixture 15 using an adhesive or a resin 19, such asan epoxy resin.

[0031] As shown in FIG. 3, the plurality of notches 15 a are formedalong the bottom surface of the needle fixture 15. The bottom surface ofthe needle fixture 15, including the plurality of notches 15 a, iscovered with the resin 19 to form a first resin layer 19 b. Whilecoating the bottom surface of the needle fixture 15 to a predetermineduniform thickness “d,” the first resin layer 19 b fills each of thenotches 15 a with a resin unit 19 a. The first resin layer 19 b coatedon the bottom surface of the needle fixture 15 and the plurality ofnotches 15 a forms a smooth, planar surface.

[0032] In addition, another jig fixes the probe needle 13 and a secondresin layer 19 d is formed at a predetermined position on the probeneedle 13. After depositing the first and the second resin layers 19 band 19 d, an exposed upper surface of the second resin layer 19 d iscontacted with an exposed bottom surface of the first resin layer 19 b,and then the first and the second resin layers 19 b and 19 d are heatedto a predetermined temperature. Thus, the first and the second resinlayers 19 b and 19 d become melted and fused, thereby affixing the probeneedle 13 to the needle fixture 15.

[0033]FIG. 4 is a schematic diagram of semiconductor inspectionequipment including the above-described probe card 10 according to anembodiment of the present invention. As shown in FIG. 4, at the bottomof the probe card 10, a wafer chuck 30 for loading an object to beinspected, e.g., a wafer W, is included. A driving means (not shown)moves the wafer chuck 30 horizontally in both the x- and y-directionsand vertically, up and down, in the z-direction. In addition, the waferchuck 30 is able to be rotated in a predetermined direction.

[0034] The wafer chuck 30 includes a heater 31 and a cooler 33 forheating or cooling a wafer W loaded on the wafer chuck 30 to apredetermined temperature condition, for example, −40° C. to +125° C.The heater 31 and the cooler 33 allow for testing to be performed undervarious temperature conditions.

[0035] In addition, a holder 40 elevates and lowers the probe card 10. Atest head 50 for transmitting a test signal is installed in the top ofthe probe card 10. At a bottom surface of the test head 50, each of aplurality of pins 51 are installed to establish contact with acorresponding one of the plurality of pin connectors 11 a of the printedcircuit board 11 to transmit an inspection signal.

[0036] The operation principle of semiconductor inspection equipmentincluding a probe card 10 according to an embodiment of the presentinvention will now be described.

[0037] Initially, the test head 50 is placed in a predeterminedposition. The holder 40 then lifts the probe card 10 and the pluralityof pins 51 at the bottom surface of the test head 50 are each contactedwith a corresponding pin connector 11 a of the printed circuit board 11to transmit an electric signal.

[0038] Sequentially, a driving means (not shown) elevates the waferchuck 30, and the electric pad (not shown) of a wafer is contacted withthe probe needle 13 to inspect an electric characteristic ofsemiconductor devices of the wafer. To ensure reliability of thecharacteristic inspection, the wafer W is tested under varioustemperature conditions. To accomplish this testing at varyingtemperatures, the heater 31 or the cooler 33 in the wafer chuck 30 heatsor cools the wafer.

[0039] According to changes in the ambient temperature, the resin 19fixing the probe needle 13 contracts or expands repeatedly. As a result,a crack is generated and the probe needle 13 may become separated fromthe needle fixture 15. The separation of the resin 19 can be preventedby the plurality of notches 15 a in the needle fixture 15, and by theresin unit 19 a filling the notches 15 a. More specifically, theplurality of notches 15 a increase the contact area with the resin 19 toprevent separation of the resin 19.

[0040] Particularly, when the plurality of notches 15 a are formed alongthe entire bottom surface of the needle fixture 15, the contact area isfurther increased so that the resin 19 may be affixed to the needlefixture 15 more securely.

[0041] As shown in FIG. 3, when the side sectional shape of theplurality of notches 15 a is a trapezoid, as illustrated in FIG. 1A, oran “Ω” shape, as illustrated in FIG. 1B, the resin unit 19 a or 19 a′ isnot easily separated when the resin 19 or 19′ is contracted under lowtemperature testing conditions.

[0042] Even though the above description is refined to a case whereinthe probe needle is a cantilever-type, the present invention may beapplied to various types of probe cards using a resin to affix the probeneedle.

[0043] As described above, in a probe card affixing a probe needle to aneedle fixture using a resin, which may be a synthetic resin, thepresent invention embodies the probe card maximizing the contact areabetween the resin and the needle fixture. Therefore, the probe card ofthe present invention prevents separation of the resin from the needlefixture to affix the probe needle more securely.

[0044] By fixing the probe needle more securely, the contact between theprobe needle and an electrode pad of an object to be inspected, e.g., asemiconductor device formed on a wafer, is improved to increaseinspection reliability. In addition, by reducing failures in which theprobe needle becomes detached from the needle fixture, the need toexchange expensive probe cards, as well as production costs, arereduced.

[0045] Preferred embodiments of the present invention have beendisclosed herein and, although specific terms are employed, they areused and are to be interpreted in a generic and descriptive sense onlyand not for purpose of limitation. Accordingly, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made without departing from the spirit and scope of thepresent invention as set forth in the following claims.

What is claimed is:
 1. A needle fixture of a probe card in semiconductorinspection equipment comprising: a printed circuit board; a needlefixture installed in the printed circuit board; a resin unit affixing aprobe needle to the needle fixture using an adhesive; and a separationpreventer for preventing separation of the resin unit from the needlefixture, wherein the separation preventer includes: a plurality ofnotches formed along a bottom surface of the needle fixture; and theadhesive filling the plurality of notches.
 2. The needle fixture of theprobe card according to claim 1, wherein the adhesive is an epoxy resin.3. The needle fixture of the probe card according to claim 1, whereinthe plurality of notches are formed along the entire bottom surface ofthe needle fixture.
 4. The needle fixture of the probe card according toclaim 1, wherein a side sectional shape of the plurality of notches is apolygon.
 5. The needle fixture of the probe card according to claim 4,wherein the polygon is a trapezoid.
 6. The needle fixture of the probecard according to claim 1, wherein a side sectional shape of theplurality of notches is a curve.
 7. The needle fixture of the probe cardaccording to claim 6, wherein the curve has the shape of the Greekletter “Ω”.
 8. A needle fixing method in a probe card of semiconductorinspection equipment fixing a probe needle to a needle fixture using anadhesive, comprising: forming a plurality of notches along a bottomsurface of the needle fixture; depositing a first resin layer on thebottom surface of the needle fixture to cover and fill the plurality ofnotches; depositing a second resin layer on a predetermined position ofthe probe needle; contacting an exposed bottom surface of the firstresin layer with an exposed upper surface of the second resin layer; andheating the first and the second resin layers to melt and fuse the firstand second resin layers.
 9. The needle fixing method in the probe cardaccording to claim 8, wherein the adhesive is an epoxy resin.
 10. Theneedle fixing method in the probe card according to claim 8, whereindepositing the first resin layer comprises: depositing the first resinlayer to a uniform predetermined thickness over and in the plurality ofnotches on the bottom surface of the needle fixture.
 11. The needlefixing method in the probe card according to claim 8, wherein theplurality of notches are formed along the entire bottom surface of theneedle fixture.
 12. The needle fixing method in the probe card accordingto claim 8, wherein a side sectional shape of the plurality of notchesis a polygon.
 13. The needle fixing method in the probe card accordingto claim 12, wherein the polygon is a trapezoid.
 14. The needle fixingmethod in the probe card according to claim 8, wherein a side sectionalshape of the plurality of notches is a curve.
 15. The needle fixingmethod in the probe card according to claim 14, wherein the curve hasthe shape of the Greek letter “Ω”.